NAME | SYNOPSIS | DESCRIPTION | HOTPROC OVERVIEW | HOTPROC CONFIGURATION | DYNAMIC CONFIGURATION | ACCESS CONFIGURATION | INSTALLATION | FILES | PCP ENVIRONMENT | DEBUGGING OPTIONS | SEE ALSO | COLOPHON
PMDAPROC(1) General Commands Manual PMDAPROC(1)
pmdaproc - process performance metrics domain agent (PMDA)
$PCP_PMDAS_DIR/proc/pmdaproc [-AL] [-D debug] [-d domain] [-l logfile] [-r cgroup] [-U username]
pmdaproc is a Performance Metrics Domain Agent (PMDA) which extracts performance metrics describing the state of the individual processes running on a Linux system. The proc PMDA exports metrics that measure the memory, processor and other resource use of each process, as well as summary information collated across all of the running processes. The PMDA uses credentials passed from the PMAPI(3) monitoring tool identifying the user requesting the information, to ensure that only values the user is allowed to access are returned by the PMDA. This involves the PMDA temporarily changing its effective user and group identifiers for the duration of requests for instances and values. In other words, system calls to extract information are performed as the user originating the request and not as a privileged user. The mechanisms available for transfer of user credentials are described further in the PCPIntro(1) page. A brief description of the pmdaproc command line options follows: -A Disables use of the credentials provided by PMAPI client tools and simply runs everything under the "root" account. Refer to the ACCESS CONFIGURATION section below for finer grained control when using pmcd(1) with remote client authentication. Only enable this option if you understand the risks involved, and are sure that all remote accesses will be from benevolent users. If enabled, unauthenticated remote PMAPI clients will be able to access potentially sensitive performance metric values which an unauthenticated PMAPI client usually would not be able to. Refer to CVE-2011-2495 and CVE-2012-3419 for additional details. -L Changes the per-process instance domain used by most pmdaproc metrics to include threads as well. -d It is absolutely crucial that the performance metrics domain number specified here is unique and consistent. That is, domain should be different for every PMDA on the one host, and the same domain number should be used for the same PMDA on all hosts. -l Location of the log file. By default, a log file named proc.log is written in the current directory of pmcd(1) when pmdaproc is started, i.e. $PCP_LOG_DIR/pmcd. If the log file cannot be created or is not writable, output is written to the standard error instead. -r Restrict the set of processes exported in the per-process instance domain to only those processes that are contained by the specified cgroup resource container. This option provides an optional finer granularity to the monitoring, and can also be used to reduce the resources consumed by pmdaproc during requests for instances and values. -U User account under which to run the agent. The default is the privileged "root" account, with seteuid (2) and setegid (2) switching for accessing most information.
The pmdaproc Performance Metrics Domain Agent (PMDA) includes an additional set of per-process metrics with an instance domain of processes restricted to an "interesting" or "hot" set. Unlike the stock metrics exported by the proc PMDA, which have an instance domain equal to the current processes, hot metrics have an instance domain which is a subset of this. This hotproc instance domain is determined by a configurable predicate evaluated over some refresh interval. As well as the equivalent per-process proc metrics, hotproc provides a cpuburn metric which specifies the CPU utilization of the process over the refresh interval, total metrics which indicate how much of the available CPU time the "interesting" processes account for, predicate metrics which show the values of the reserved variables (see below) that are being used in the hotproc predicate, and control metrics for controlling the agent.
The configuration file consists of one predicate used to determine if a process should be in the interesting set or not. An example configuration file may be found at $PCP_PMDAS_DIR/proc/samplehotproc.conf This file with any modifications can be copied to $PCP_PMDAS_DIR/proc/hotproc.conf in order to configure the hot metrics. The pmstore(1) and pmStore(3) interfaces can be used as well (described below). The predicate is described using the language specified below. The symbols are based on those used by the C(1) and awk(1) languages. Boolean Connectives && (and), || (or), ! (not), () (precedence overriding) Number comparators < , <= , > , >= , == , != String comparators == , != String/Pattern comparators ~ (string matches pattern) , !~ (string does not match pattern) Reserved variables uid (user id; type integer) uname (user name; type string), gid (group id; type integer) gname (group name; type string), fname (process file name; type string), psargs (process file name with args; type string), cpuburn (cpu utilization; type float), iodemand (I/O demand - Kbytes read/written per second; type float), ctxswitch (number of context switches per second; type float), syscalls (number of system calls per second; type float), virtualsize (virtual size in Kbytes; type float), residentsize (resident size in Kbytes; type float), iowait (blocked and raw io wait in secs/sec; type float), schedwait (time waiting in run queue in secs/sec; type float). Literal values 1234 (positive integer), 0.35 (positive float), "foobar" (string; delimited by "), /[fF](o)+bar/ (pattern; delimited by /), true (boolean), false (boolean) Comments #this is a comment (from # to the end of the line). Examples cpuburn > 0.2 # cpu utilization of more than 20% cpuburn > 0.2 && uname == "root" cpuburn > 0.2 && (uname == "root" || uname == "hot") psargs ~ /pmda/ && cpuburn > 0.4 The hotproc.predicate metrics may be used to see what the values of the reserved variables are that were used by the predicate at the last refresh. They do not cover the reserved variables which are already exported elsewhere. A hotproc.predicate metric may not have a value if it is not referenced in the configuration predicate.
The hot process metrics can also be configured at runtime through the pmstore(1) interface (and, implicitly, the pmStore(3) API) Examples pmstore hotproc.control.config 'fname == "mingetty"' pmstore hotproc.control.config 'uid == 0' To force the config file to be reloaded: pmstore hotproc.control.reload_config "1"
Access to per-process metrics is controlled by several factors. When using automatically authenticating local connections, such as through the "unix:" or "local:" style context, then client tools will have full access to these metrics as if sampling the metrics directly as the user running the client tool. When using pmcd with remote, authenticated clients it is possible to specify a set of user names that are allowed access to the process metrics. A configuration file $PCP_SYSCONF_DIR/proc/access.conf can be used to fine-tune this behaviour, and it supports two keywords: allowed A comma-separated list of authenticated user names that will be allowed access to per-process metrics. Sampling is performed as the root user. mapped A boolean value, when true indicating that authenticated user names will be mapped to local system user account names (this requires a one-to-one user name mapping between the account and the SASL-based authenticated user name enforced by pmcd(1)). Sampling is performed as that local user.
The proc PMDA is installed and available by default. If you want to undo the installation, do the following as root: # cd $PCP_PMDAS_DIR/proc # ./Remove If you want to establish access to the names, help text and values for the proc performance metrics once more, after removal, do the following as root: # cd $PCP_PMDAS_DIR/proc # ./Install pmdaproc is launched by pmcd(1) and should never be executed directly. The Install and Remove scripts notify pmcd(1) when the agent is installed or removed.
$PCP_PMCDCONF_PATH command line options used to launch pmdaproc $PCP_PMDAS_DIR/proc/help default help text file for the proc metrics $PCP_PMDAS_DIR/proc/Install installation script for the pmdaproc agent $PCP_PMDAS_DIR/proc/Remove undo installation script for the pmdaproc agent $PCP_LOG_DIR/pmcd/proc.log default log file for error messages and other information from pmdaproc $PCP_PMDAS_DIR/proc/samplehotproc.conf simple sample hotproc configuration $PCP_PMDAS_DIR/proc/hotproc.conf default hotproc configuration file $PCP_SYSCONF_DIR/proc/access.conf default access control configuration file
Environment variables with the prefix PCP_ are used to parameterize the file and directory names used by PCP. On each installation, the file /etc/pcp.conf contains the local values for these variables. The $PCP_CONF variable may be used to specify an alternative configuration file, as described in pcp.conf(5).
The -D or --debug option enables the output of additional diagnostics on stderr to help triage problems, although the information is sometimes cryptic and primarily intended to provide guidance for developers rather end-users. debug is a comma separated list of debugging options; use pmdbg(1) with the -l option to obtain a list of the available debugging options and their meaning. Debugging options specific to pmdaproc are as follows: ┌────────┬───────────────────────────────────────────────┐ │ Option │ Description │ ├────────┼───────────────────────────────────────────────┤ │ appl0 │ cgroup handling │ ├────────┼───────────────────────────────────────────────┤ │ appl1 │ refresh processing, including hotproc metrics │ ├────────┼───────────────────────────────────────────────┤ │ appl2 │ PMNS operations │ ├────────┼───────────────────────────────────────────────┤ │ appl3 │ process accounting metrics │ └────────┴───────────────────────────────────────────────┘
PCPIntro(1), pmcd(1), pmstore(1), seteuid(2), setegid(2), PMAPI(3), pcp.conf(5) and pcp.env(5).
This page is part of the PCP (Performance Co-Pilot) project. Information about the project can be found at ⟨http://www.pcp.io/⟩. If you have a bug report for this manual page, send it to pcp@groups.io. This page was obtained from the project's upstream Git repository ⟨https://github.com/performancecopilot/pcp.git⟩ on 2025年08月11日. (At that time, the date of the most recent commit that was found in the repository was 2025年08月11日.) If you discover any rendering problems in this HTML version of the page, or you believe there is a better or more up-to-date source for the page, or you have corrections or improvements to the information in this COLOPHON (which is not part of the original manual page), send a mail to man-pages@man7.org Performance Co-Pilot PCP PMDAPROC(1)
Pages that refer to this page: pcp-atop(1), pcp-atopsar(1), pmdaoverhead(1), pmda(3), LOGARCHIVE(5)
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